Militaries around the world use military combat training systems to help train military personnel for battle. To more realistically simulate battle conditions, military combat training systems have been developed that allow for the military personnel to use actual military equipment and weaponry during the battle field training exercises. Firearms used by participants in such battle field exercises may be mounted with laser transmission systems, and may also be loaded with blank munitions to closely simulate actual firing conditions. The laser transmission systems generate a laser that travels along an approximated bullet trajectory. Participants wear or otherwise carry a laser receiver system that registers a “hit” when struck by a laser.
Some automatic weapons used in such exercises depend on high pressures in the chamber generated by the combustion of the propellant to cycle the firearm and chamber the next round. If a blank munition is used, there is no bullet to seal the barrel, and the combustion gases exit through the muzzle without building up enough pressure to chamber the next round. In these circumstances a blank fire adaptor (BFA) is used. A BFA fits on the end of the barrel of a firearm and partially blocks the muzzle of the firearm, thereby causing sufficient pressure in the chamber to cycle the weapon and chamber the next round.
Some laser transmission systems initiate transmission of the laser based on a detected vibration of the firearm, such as the vibration associated with the discharge of the blank munition. Unfortunately, this enables a participant to “cheat” by causing the laser transmission system to initiate transmission of the laser by simply striking the firearm with an object. Other laser transmission systems initiate transmission of the laser using an acoustic sensor to detect the actuation of the trigger. The sensitivity levels needed to measure trigger actuation make these laser transmission systems vulnerable to noise and still enable a participant to cheat.
More recently, laser transmission systems have been developed that initiate transmission of the laser by measuring both the mechanical vibrations associated with a discharge of the munition and the subsequent sound or flash at the muzzle of the firearm caused by the discharge of the munition. Such subsequent sound or flash may be referred to herein as a “flash event.” Delaying transmission of the laser until, or after, detection of the flash event greatly reduces, or eliminates, cheating by a participant.
Unfortunately, especially when a BFA is used, the forces associated with a flash event tend to cause the barrel of the firearm to skew, or deviate, from the direction it is aimed. Consequently, a laser transmission system used with a machine gun that includes a BFA, and that relies upon detection of the flash event to initiate transmission of the laser, necessarily initiates transmission of the laser after a point in time that the barrel has begun to deviate from the target due to the forces associated with the flash event. This deviation also causes the laser to deviate from the target, and may result in a “miss” rather than a “hit,” even though the firearm was properly and accurately aimed at the target when the trigger was pulled. This sequence of events makes it difficult to assess the aiming accuracy of the participant.
In an attempt to compensate for transmitting the laser after the barrel has begun to deviate, manufacturers have increased laser power to increase the diameter of the bloom of the laser to increase the likelihood that the edge of the bloom will contact the laser receiver system. However, the increased laser diameter only partially compensates for the barrel deviation, and unfortunately the increase in laser power causes such laser systems to not be “eye-safe.” Laser systems that are not eye-safe may not be practical in many training exercises, or may require additional protective material to be worn by participants, reducing the realism of the exercise.
Accordingly, there is a need for a laser transmission system that accurately approximates a bullet trajectory and prevents military personnel from initiating transmission of the laser without actually firing a munition.